test: Add unit tests for config operations, common utilities (#295)

* test: Add unit tests for config operations, common utilities, and CLI commands, including test data.

Signed-off-by: SharanRP <z8903830@gmail.com>

* chore: Remove trailing blank line from ops_test.go.

Signed-off-by: SharanRP <z8903830@gmail.com>

---------

Signed-off-by: SharanRP <z8903830@gmail.com>

Author: SharanRP

pkg/cmd/version/version_test.go

@@ -0,0 +1,122 @@
+package version
+
+import (
+	"testing"
+)
+
+func TestVersionCmd_Properties(t *testing.T) {
+	t.Run("Use field is correct", func(t *testing.T) {
+		if VersionCmd.Use != "version" {
+			t.Errorf("VersionCmd.Use = %q, want %q", VersionCmd.Use, "version")
+		}
+	})
+
+	t.Run("Short description is set", func(t *testing.T) {
+		if VersionCmd.Short == "" {
+			t.Error("VersionCmd.Short should not be empty")
+		}
+		expected := "Displays the version of litmusctl"
+		if VersionCmd.Short != expected {
+			t.Errorf("VersionCmd.Short = %q, want %q", VersionCmd.Short, expected)
+		}
+	})
+
+	t.Run("Command is runnable", func(t *testing.T) {
+		if VersionCmd.Run == nil {
+			t.Error("VersionCmd.Run should not be nil")
+		}
+	})
+}
+
+func TestUpdateCmd_Properties(t *testing.T) {
+	t.Run("Use field is correct", func(t *testing.T) {
+		if UpdateCmd.Use != "update" {
+			t.Errorf("UpdateCmd.Use = %q, want %q", UpdateCmd.Use, "update")
+		}
+	})
+
+	t.Run("Short description is set", func(t *testing.T) {
+		if UpdateCmd.Short == "" {
+			t.Error("UpdateCmd.Short should not be empty")
+		}
+		expected := "Changes the version of litmusctl"
+		if UpdateCmd.Short != expected {
+			t.Errorf("UpdateCmd.Short = %q, want %q", UpdateCmd.Short, expected)
+		}
+	})
+
+	t.Run("Requires exactly one argument", func(t *testing.T) {
+		if UpdateCmd.Args == nil {
+			t.Error("UpdateCmd.Args should not be nil")
+		}
+	})
+
+	t.Run("Command is runnable", func(t *testing.T) {
+		if UpdateCmd.Run == nil {
+			t.Error("UpdateCmd.Run should not be nil")
+		}
+	})
+}
+
+func TestVersionCmd_Subcommands(t *testing.T) {
+	t.Run("UpdateCmd is subcommand of VersionCmd", func(t *testing.T) {
+		found := false
+		for _, cmd := range VersionCmd.Commands() {
+			if cmd.Use == "update" {
+				found = true
+				break
+			}
+		}
+		if !found {
+			t.Error("UpdateCmd should be a subcommand of VersionCmd")
+		}
+	})
+
+	t.Run("VersionCmd has exactly one subcommand", func(t *testing.T) {
+		cmdCount := len(VersionCmd.Commands())
+		if cmdCount != 1 {
+			t.Errorf("VersionCmd has %d subcommands, want 1", cmdCount)
+		}
+	})
+}
+
+func TestVersionCmd_Help(t *testing.T) {
+	t.Run("Command has help available", func(t *testing.T) {
+		if VersionCmd.UsageString() == "" {
+			t.Error("Usage string should not be empty")
+		}
+	})
+}
+
+func TestUpdateCmd_ArgsValidation(t *testing.T) {
+	tests := []struct {
+		name    string
+		args    []string
+		wantErr bool
+	}{
+		{
+			name:    "no arguments",
+			args:    []string{},
+			wantErr: true,
+		},
+		{
+			name:    "one argument (valid)",
+			args:    []string{"0.23.0"},
+			wantErr: false,
+		},
+		{
+			name:    "two arguments",
+			args:    []string{"0.23.0", "extra"},
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := UpdateCmd.Args(UpdateCmd, tt.args)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("UpdateCmd.Args() with %v error = %v, wantErr %v", tt.args, err, tt.wantErr)
+			}
+		})
+	}
+}